import java.util.Scanner;

public class Traning09 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入班级人数");
        int num = sc.nextInt();
        double[] score = new double[num];
        int gt80 = 0;
        int gt70 = 0;
        int gt60 = 0;
        int lt60 = 0;
        double sum = 0;
        for (int i = 0; i< score.length; i++){
            System.out.println("请输入学号是"+(i + 1)+"学生的成绩：");
            score[i] = sc.nextInt();
            sum = sum + score[i];
            if (score[i] >=80){
    gt80++;
            }else if (score[i] >=70){
    gt70++;
            }else if (score[i]>=60){
                gt60++;
            }else if (score[i]>=0){
                lt60++;
            }else{
                System.out.println("第"+(i+1)+"成绩格式错误");
            }
        }
        double avg = sum/score.length;
        System.out.println("全班平均成绩为："+avg);
        System.out.println("成绩大于80："+gt80);
        System.out.println("成绩大于70："+gt70);
        System.out.println("成绩大于60："+gt60);
        System.out.println("成绩不及格人数："+lt60);
        }
    }

